Consequences of changing MIDI file suffix

[Matthias Neeracher]

I'm currently thinking of patching lilypond on MacOS X so MIDI files 
are generated with a suffix of .midi instead of .mid, as the former is 
automatically recognized by QuickTime as a MIDI file, while the latter 
is not.

From my perusal of the source code, it seemed to me that the change 
wouldn't be too difficult for me to make, but I'm wondering whether 
there are interactions between the lilypond tools that I've overlooked.

Is there anything that would argue against making this change on MacOS 
X?

Matthias